fix(sfc): avoid auto name inference leading to unwanted recursion

fix #5965
fix #6027
fix #6029

packages/compiler-sfc/__tests__/__snapshots__/compileScript.spec.ts.snap

@@ -2,7 +2,7 @@
 
 exports[`SFC analyze <script> bindings auto name inference basic 1`] = `
 "export default {
-  name: 'FooBar',
+  __name: 'FooBar',
   setup(__props, { expose }) {
   expose();
 const a = 1

packages/compiler-sfc/__tests__/compileScript.spec.ts

@@ -1650,7 +1650,7 @@ describe('SFC analyze <script> bindings', () => {
         }
       )
       expect(content).toMatch(`export default {
-  name: 'FooBar'`)
+  __name: 'FooBar'`)
       assertCode(content)
     })